Package accumulating conveyor

ABSTRACT

Packages are temporarily accumulated from a main conveyor line, in the event of a blockage of the packages from normal movement therealong, and are subsequently redelivered to the main conveyor line by a reversible conveyor apparatus for moving packages in either of two opposite directions away from and toward the main conveyor line. Control over movement of packages on the accumulating conveyor is exercised in response to sensing of the presence and absence of the excessive number of packages on the main conveyor line as pointed out more fully hereinafter.

United States Patent Chalich 1 June 13, 1972 [54] PACKAGE ACCUMULATINGCONVEYOR [72] Inventor: Charles Chalich, Salisbury, NC.

[73] Assignee: Taylor Manufacturing Company, Salisbury, NC.

[22] Filed: Nov. 13, 1970 [2]] Appl.N0.: 89,249

[52] US. Cl ..l98/102, 198/76 [51] Int. Cl. 58] Field of Search [5 6]References Cited UNITED STATES PATENTS 3,442,401 5/1969 Wolfe et a]...2l4/l6 B X 2,462,021 2/ 1949 l-larker 198/37 X Primary Examiner-EvenC. Blunk Assistant ExaminerD0uglas D. Watts Attorney-Parrott, Bell,Seltzer, Park & Gibson [57] ABSTRACT Packages are temporarilyaccumulated from a main conveyor line, in the event of a blockage of thepackages from normal movement therealong, and are subsequentlyredelivered to the main conveyor line by a reversible conveyor apparatusfor moving packages in either of two opposite directions away from andtoward the main conveyor line. Control over movement of packages on theaccumulating conveyor is exercised in response to sensing of thepresence and absence of the excessive number of packages on the mainconveyor line as pointed out more fully hereinafter.

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PATENTED UN 13 m2 SHEEI 4 OF 4 INVENTORS CHARLE$ CHAucH mMMgM,M{/mATTORNEYS PACKAGE ACCUMULATING CONVEYOR Due to the relatively greatspeeds at which automatic processing machinery may perform individualoperations, it is conventional to use package transporting conveyorsystems in conjunction with such automatic machinery. One example of theapplication of a package transporting conveyor system in conjunctionwith automatic machinery is the handling of cartons and bottles inconjunction with the packaging of liquid products such as soft drinks,beer and milk. In such opera-. tions, it is conventional for bottles,cans orcartons to move between various automatic machines along a mainconveyor line linking the machines and normally moving packages along apredetermined path of travel.

As is well known to persons familiar with such package transportingconveyor systems, the automatic machines linked' by such a system do notalways operate at a common package handling rate. For example, a bottlefilling machine and a carton packing machine are capable of handlingpackages at differing rates, but the slower bottle filling machine istypically less subject to jams and interruptions than is the cartonpacking machine.

As a result of such characteristics of machines used in conjunction withpackage transporting conveyor systems, and also in view of occasionaljamming of packages moving along a main conveyor line, it is desirableto provide for continuing operation of the slower automatic machineseven though packages may be blocked from normal movement along thepredetermined path of travel at some point downstream of the automaticmachine. The accomplishment of such continuing operation contributes toachieving the greatest possible effciency for the overall processingoperation, as may be understood.

I-Ieretofore, such ends have been attained by temporarily accumulatingpackages from a main conveyor line and subsequently redelivering theaccumulated packages thereto, diverting packages from the main conveyorline to a circulating secondary conveyor. Diverted packages, inaccordance with such prior practices, were permitted to circulate on thesecondary conveyor until such time as continued movement along the mainconveyor line again became possible, with the bottles then beingdiverted from the secondary conveyor back onto the main conveyor line.

Such circulating secondary conveyors have commonly brought about rubbingor turning of diverted packages one against the other. In instanceswhere the packages being handled are bottles or cans, such rubbing leadsto breakage or scarring of the packages, while cartons so diverted aresubject to being overturned. In any instance, a secondary conveyor forthe recirculation of accumulated packages has not been a satisfactorysolution.

It is an object of the present invention to accommodate fluctuations inthe flow rate of packages normally moving with a main conveyor linealong a predetermined path of travel by temporarily accumulatingpackages from the conveyor line, transporting accumulated packages awayfrom the main conveyor line along a path perpendicular to thepredetermined path of travel, and subsequently redelivering theaccumulated packages to the main conveyor line by moving the packages ina reversed direction, toward the main conveyor line. By thusaccumulating and redelivering packages through movement away from andtoward the main conveyor line, the rubbing rotation heretofore typicalof recirculating secondary conveyors is avoided and the deficiencies ofsuch conveyors are overcome. In accomplishing this object of the presentinvention, a reversing conveyor means is provided, with movement of thereversing conveyor means being controlled in response to the presenceand absence of excessive numbers of packages on the main conveyor line.

A further object of the present invention is to stabilize conveyedpackages in a desired orientation during accumulation and redeliverythereof, to thereby facilitate maintenance of engaged packages in thenormal orientation and further reduce the likelihood of overturning ordamage of the packages. In accomplishing this object of the presentinvention, package stabilizing rail means are mounted in predeterminedrelation to the reversible accumulating conveyor means, for engagingpackages moving onto the conveyor means.

Yet a further objectof the present invention is the simplification ofdrive arrangements for moving packages in either of two oppositedirections along a predetermined path of travel, through the provisionof a reversible conveyor apparatus particularly constructed and arrangedfor transmittal of motive power in either of opposite rotational.directions to a flexible endless loop conveyor member. In accordancewith this object of the present invention, support means for theflexible endless loop conveyor member are particularly constructed andarranged to accommodate the presence of a catenary curve in the conveyormember at an upper horizontal run of the path along which the conveyormember moves.

Some of the objects and advantages of the invention having been stated,others will appear as the description proceeds, when taken in connectionwith the accompanying drawings, in which FIG. 1 is a plan view of apackage transporting conveyor system incorporating the presentinvention;

FIG. 2 is an elevation view, in partial section, taken generally asindicated by the line 2-2 inFlG. 1;

FIG. 3 is an elevation view, partially in section, taken generally asindicated by the line 3-3 in FIG. 1;

FIG. 4 is a perspective view of portions of the apparatus of FIGS. 1-3,particularly illustrating a package stabilizing rail means in accordancewith the present invention; and

FIG. 5 is a schematic wiring diagram of an electrical control means forthe package transporting conveyor system of FIGS. 1-4.

By way of an illustrative embodiment for making the present inventionmore readily understandable, FIGS. 1-5 particularly illustrate a packagetransporting conveyor system constructed and arranged for use in abottling plant having a main conveyor line 10 normally moving packagesalong a predetermined path of travel, such as from the left to the rightin FIG. 1. In the form illustrated, the main conveyor line 10 comprisestwo parallel runs of chained conveyor plates 11. As is generally knownto persons skilled in the art of package transporting conveyor systems,elements such as the plates 11 may be connected into flexible, endlessloop conveyor members for receiving and transporting packages with theendless loop conveyor members normally being supported by appropriatesprocket means and stationary support means to provide for transmittalof driving motive power thereto. As illustrated somewhat schematicallyin FIG. 2, underlying support means 12 and sprockets 14 may engage theconveyor members formed by the plates 11 so that the main conveyor linedefines a generally horizontal package supporting surface for receivingconveyed packages such as bottles B (FIG. 2 and phantom line circles inFIG. 1).

For various of the reasons briefly mentioned above, bottles B will fromtime to time be blocked from normal movement along the predeterminedpath of travel defined by the main conveyor line 10, as in the event ofan interruption in the operation of an automatic machine or in the eventof jamming of the bottles. Upon such blockage, bottles B rapidly buildup along the main conveyor line 10 inasmuch as movement of the mainconveyor line 10 is not interrupted. In accordance with the presentinvention, packages are temporarily accumulated from the main conveyorline and subsequently redelivered thereto by an accumulating means whichcomprises a reversible accumulating conveyor generally indicated at 20and mounted adjacent the main conveyor line 10 for package transportingmovement away from and toward the main conveyor line along a pathperpendicular to the predetermined path of travel defined by the mainconveyor line.

In the illustrated embodiment, and. as will be more fully pointed outhereinafter, the accumulating conveyor means 20 comprises a plurality offlexible, endless conveyor members formed by chained together plates 21(six flexible endless conveyor members being shown in FIG. 1). By meansof suitable upright standards 22, 24 (FIG. 2) and side frame members 25,26 (FIGS. 2 and 3), the accumulating conveyor means 20 is supported todefine a generally horizontal package supporting surface lyingsubstantially in a common plane with a generally horizontal packagesupporting surface of the main conveyor line 10 (FIGS. 2 and 4). Thus,bottles B may move back and forth between the main conveyor line 10 andthe accumulating conveyor means 20 at a package receiving and deliveringlocation which is more particularly defined by a dead plate 28 (FIG. 4);

As will be understood, it is desirable for the main conveyor line 10 andthe accumulating conveyor means 20 to as nearly intersect as ispossible. Nevertheless, due to the necessary reversal in direction ofthe accumulating conveyor means 20 adjacent the side edge of the mainconveyor line 10, the radius of movement required (as indicated by FIGS.2 and 4) necessitates the use of the dead plate 28 in order to ensurethe horizontal package supporting surface is continuous between theplates 11 and the main conveyor line 10 and the plates 21 of theaccumulating conveyor means 20.

The plurality of flexible, endless loop conveyor members which togetherform the accumulating conveyor means 20 are supported for movement abouta predetermined closed path of travel by sprocket means and stationarysupport means mounted from the standards 22, 24 and frame side plates25, 26. In particular, a front cross shaft 29 (FIG. 3) is mounted forrotation by bearings 30, 31 secured to the side plate members 25, 26 andcarries front conveyor member sprockets 32, 34. Due to the partialbreaking away of FIG. 3 in order to illustrate the details of thepresent invention with greater clarity, only two front conveyorsprockets are illustrated, but it is to be understood that each of theflexible, endless loop conveyor members formed by chained togetherplates 21 is provided with a corresponding sprocket. Each of theflexible, endless loop conveyor members additionally passes inengagement with a corresponding driven sprocket, such as the drivensprocket 35 in FIG. 2. The driven sprockets are mounted together on adriven cross shaft 36, for rotation therewith under impetus provided bya reversing drive means generally indicated at 38. Desirably, thereversing drive means 38 includes a reversible electrical motor 39 (FIG.a suitable manually variable transmission to permit variance in thefinal output speed obtained from the reversing drive means 38, and adrive chain 40 operatively connecting the reversing drive means 38 tothe driven shaft 36.

As will be understood, the front sprocket members 32, 34 andcorresponding ones of the driven sprockets such as the sprocket 35cooperate in supporting the flexible endless loop conveyor members formovement about a predetermined closed path of travel including agenerally horizontal upper run and a lower run. In accordance with thepresent invention, the conveyor members are supported in the upper runby stationary support means 41 which underlie the conveyor members alongthe horizontal path. Further, stationary supporting bars 42, 44 arepositioned in spaced locations below the lower run of the endless loopconveyor members.

In accordance with an important feature of the present invention, thedriven sprocket 35 cooperates in a particular manner with the stationarysupport means 41 for accomplishing reversing drive of the endless loopconveyor members in a particularly advantageous manner. As is generallyknown to designers of conveyor systems employing plates such as themembers 21 which are chained together to form an endless loop conveyormember, it is desirable that the conveyor member be pulled along ahorizontal path portion in which a package supporting surface isdefined, due to difficulties encountered in pushing such flexible,endless loop conveyor members. Typically, in accordance with such priorart practices, allowance is made for the conveyor member to assume, onthe lower horizontal run, a catenary curve to accommodate slackness inthe endless loop conveyor member coming about through wear of the platemembers or manufacturing tolerances.

In accordance with the present invention, the stationary support means41 extends from a location adjacent the main conveyor line 10 to a pointspaced from the driven sprocket 35 (FIG. 2) for accommodating thepresence of the catenary curve portion of the conveyor member betweenthe driven sprocket 35 and the stationary support means 41 (as indicatedby phantom lines in FIG. 2). Particularly in the instance of the presentinvention, where a plurality of flexible, endless loop conveyor membersare arranged side by side, the spacing of the stationary support meansfrom the driven sprocket 35 provides accommodation for varying degreesof slackness among the plurality of conveyor members. Reversible driveof the accumulating means 20 is accommodated in that tension may bepresent in the upper horizontal run of the conveyor members while theconveyor is driven in movement away from the main conveyor line 10,while tension may be present in the lower horizontal run as theaccumulating conveyor means 20 is driven in movement toward the mainconveyor line I0. In either instance, the necessary accommodation ofslack in the endless loop conveyor members is provided, by theaccommodation of the catenary curve portion of the conveyor member alongthe conveyor run which is not under tension.

Package transporting movement of the accumulating conveyor means 20 awayfrom and toward the main conveyor line 10, under the impetus provided bythe driving means 38, occurs through the operation of a control meanswhich includes means, as shall now be described, for sensing thepresence and absence of an excessive numbers of packages on the mainconveyor line 10. By such sensing of packages on the main conveyor line10, the control means responds to the occurrence of a blockage of normalpackage movement along the main conveyor line by driving theaccumulating conveyor means 20 in movement away from the main conveyorline 10 so as to move packages away from the predetermined path oftravel. Further, the control means responds to resumption of normalpackage movement along the main conveyor line 10 by driving theaccumulating conveyor means 20 in movement toward the main conveyor lineso as to return packages to the predetermined path of travel. Suchcontrol is accomplished through the cooperation of the elements ofelectrical circuitry schematically illustrated in FIG. 5, which arerelated to main conveyor line 10 and accumulating conveyor means 20 asthere schematically illustrated and as more fully shown in FIGS. 1-3.

In accordance with the present invention, the energization of theelectrical drive motor 39, and thus the direction of rotation impartedthereby to the driven shaft 36, is determined by a forward drive relaygenerally indicated at 50 and a reverse drive relay generally indicatedat 51. The relays include respective control windings 52, 53 andassociated contact sets 52a, 52b, 52c, 52d, 53a, 53b, 53c, 53d. In eachinstance, the contact sets identified by the subscripts a, b and 0control the interconnection of the motor 39 with a source of three-phaseelectrical current, to thereby control the direction of the rotation ofthe motor 39. Energization of the respective windings 52 and 53 of theforward relay 50 and reverse relay 51 is governed by the interaction ofa plurality of sensing devices, in the form of electrical switches LS1,LS2, LS3, LS4, and LS5, together with time delay relays generallyindicated at 55 and 56. Each of the time delay relays includes arespective control winding 57, 58 and contact set 57a, 58a controlledthereby. The functions and cooperation of the various elements of thecontrol means shall be brought out more fully in the discussion whichfollows.

The primary control over timing as to when the accumulating conveyormeans 20 is to be driven and over determination of the direction inwhich the accumulating conveyor means 20 is to move are accomplished bya limit switch LS1 positioned adjacent the package receiving anddelivering location and a limit switch LS2 positioned along the mainconveyor line 10 downstream of the accumulating conveyor means 20. Thedownstream limit switch LS2 detects crowding of packages along the mainconveyor line 10 downstream of the accumulating conveyor means 20 by theprovision of an actuating rail 60. As will be understood, upon asubsequent clearance of the blockage, so that bottles B move properlyalong the main conveyor line 10, the actuating lever for the limitswitch LS2 will be released to swing outward to the position indicatedin FIGS. 1 and 2. As will be noted from FIG. 5, the limit switch LS2includes a first contact set which is normally closed during normalmovement of packages along the main conveyor line (as indicated by thepositions illustrated in FIGS. 1, 2 and 5) and a second contact setnormally open during normal movement of packages along the main conveyorline 10. In the event of a blockage of packages and the build up of anexcessive number along the main conveyor line 10, the normally closedcontact set is open and the normally open contact set is closed.

With the build up of packages along the main conveyor line 10, packagesultimately become crowded between the edge rail 60 of the main conveyorline 10 and a package stabilizing rail means generally indicated at 61which is mounted in predetermined relation to the accumulating conveyormeans for normally forming a portion of an edge rail extending along theother side of the main conveyor line from the edge rail 60. The packagestabilizing rail means serves at least two functions in the apparatus ofthe present invention, one of which is to cooperate with a limit switchLS1 in determining when the accumulating conveyor means 20 is to bedriven by the drive means 38. In particular, as crowding of bottles Balong the main conveyor line 10 continues, bottles are crowded onto theaccumulating conveyor means 20 across the dead plate 28 and move thepackage stabilizing rail means 61 away from a position overlying thedead plate 28 in which the rail means 61 normally forms a portion of anedge rail extending along the main conveyor line 10. With such movementof the package stabilizing rail means 61, the crowding limit switch LS1is closed, energizing one of the timing relays 55, 56 through whichevercontact set of the downstream limit switch LS2 is closed. At initialcrowding of bottles onto the accumulating conveyor means 20, theconductive state of the downstream limit switch LS2 is such that thewinding 57 of the timing relay 55 is energized. After a predeterminedinterval of time, established in order to avoid excessively quickcycling of the drive means 38, the contact set 57a of the time delayrelay 55 closes, energizing the winding 52 of the reverse drive relay55, through contacts of a full table limit switch LS3 and contact set53b of the forward relay 51. With energization of the winding 52 of thereverse relay 50, the associated contact set 52a, 52b and 52c areclosed, energizing the drive motor 39 and transmitting rotational motivepower to the accumulating conveyor means 20 to move the same away fromthe main conveyor line 10. The bottles B crowding onto the accumulatingconveyor means 20 are thus transported away from the main conveyor linein accommodation of the overflow condition then current.

With subsequent clearing of the blockage downstream of the accumulatingconveyor means 20, the conductive state of the contacts of thedownstream limit switch LS2 changes, deenergizing the winding 57 of thetiming relay 55, interrupting energization of the winding 52 of thereverse relay 50, and thereby de-energizing the drive motor 39. At thesame time, the winding 58 of the timing relay 56 is energized and, aftera suitable delay interval, closure of the contact set 58a occurs. Uponsuch contact closure, the winding 53 of the forward relay 51 isenergized, through the contact set 52d of the reverse relay 50. Closureof the contact sets 53a, 53b, 53c then energizes the drive motor 39 tomove the accumulating conveyor means 20 toward the main conveyor line10, redelivering accumulated packages to the main. conveyor line.

The control means of the present invention contemplates cooperation withthe primary limit switches LSI, LS2 of secondary limit switches LS3,LS4, and LS5 which provide safety interlocks in the event of certainoperational occurrences otherwise possibly leading to damages toconveyed packages or to the conveyor system.

More particularly as packages are accumulated on the accumulatingconveyor means 20, the package stabilizing rail means 61 moves with theconveyor means away from the main conveyor line 10. In the event thatthe available area on the accumulating conveyor means 20 becomes fullycrowded with accumulated packages, it is desirable to stop furtherdriving of the accumulating conveyor means 20. This desired controlfunction is accomplished through the cooperation of the limit switchesLS3 and LS5, which together sense the presence on the accumulatingconveyor means of such number of packages as to fill the capacitythereof for temporary accumulation of packages. More particularly,movement of the stabilizing rail means 61 to a position fully withdrawnfrom the main conveyor line 10 brings such stabilizing rail means intocontact with a full table limit switch LS3, opening contacts thereof andthereby opening one of two parallel circuits between the contact set 57aof the timing relay and the winding 52 of the reverse driving relay 50.Continued accumulation of packages on the accumulating conveyor means 20ultimately results in such crowding of packages thereonto as to engagean operating lever for a front table limit switch LS5, swinging suchoperating lever to one side and opening the other parallel branchcircuit. With such opening of the circuit, the winding 52 of the reversedriving relay 50 becomes fully de-energized, and energization of thedrive motor 39 is interrupted.

During redelivery of packages from the accumulating conveyor means tothe main conveyor line, an opposing limit switch LS4 senses theredelivery of such number of packages as to momentarily fill thecapacity of the main conveyor line to move packages along thepredetermined path of travel, in that excessive delivery of packageswill result in temporary crowding between the package receiving andredelivery relocation and the side rail 60 of the main conveyor line 10.Such crowding pivots an actuation arm of the opposing limit switch LS4,opening the contacts thereof and de-energizing the winding 58 of thetiming relay 56. In such an event, movement of the accumulating conveyormeans 20 toward the main conveyor line 10 is interrupted until such timeas normal movement of packages along the main conveyor line 10 clear theovercrowded condition adjacent the opposing limit switch LS4.

One function served by the package accumulating rail means 61, throughits cooperation with the control means of the present invention, hasbeen disclosed hereinabove. It is to be noted that the packagestabilizing rail means 61 has other and further important functions inthe system of the present invention, in that the rail means 61 is bothmovable relative to the accumulating conveyor means 20' and movestherewith,

for engaging packages crowded onto the accumulating conveyor means 20and for thereby facilitating maintenance of an engaged package in adesired orientation on the package supporting surface provided by theaccumulating conveyor means 20. In particular, it is to be noted thatthe package stabilizing rail means 61 comprises a frame including anabutment member 62 mounted from side plate members 64, 65 which restsupon the plate 21 of the accumulating conveyor means 20 through means ofskid members 66,. 68. Extending through the side plate members 65, 64 isa cross shaft bearing sprocket members 71, 72 adjacent opposite endsthereof. The sprocket members 71, 72 engage endless chains 73, 74 whichmove with the endless conveyor members of the accumulating conveyormeans 20 as the conveyor means 20 is driven in movement away from andtoward the main conveyor line 10. The cross shaft 70 is free to rotaterelative to the side frame members 64, 65 in order that the packagestabilizing rail means may be both movable relative to the accumulatingconveyor means 20 and movable with the accumulating conveyor means 20.

More particularly, if no other forces are exerted on the packagestabilizing rail means 61, the rail means 61 will move away from andtoward the main conveyor line with movement of the accumulating conveyormeans 20. However, should the package stabilizing rail means 61encounter a limiting abutment, such as the rear frame 75 of theaccumulating conveyor means or the forward frame portion thereof,continued movement of the chains 73, 74 will cause rotation of thesprockets 71, 72 without translational movement of the rail means 61.Further, in the event that the accumulating conveyor means 20 ismomentarily stationary and force is applied to the rail means 61 as uponthe crowding of bottles across the dead plate 28, movement of thesprockets 71, 72 along the chains 73, 74 accommodates movement of thestabilizing rail means 61 relative to the accumulating conveyor means20.

The operative relationship between the rail means 61 and theaccumulating conveyor means 20 has importance, beyond the controlfunctions disclosed hereinabove, in that the maintenance of packages ina desired orientation on the package supporting surfaces of the conveyormeans 20 and the main conveyor line 10, without rotation or otherrelative movement of the packages, is accomplished at least part by theabsence of relative movement between the packages and the stabilizingrail means during transitional movement of the packages across the deadplate 28 between the main conveyor line 10 and the accumulating conveyormeans 20. Such reception of packages crowded on the accumulatingconveyor means 20 or redelivery of packages therefrom onto the mainconveyor line 10 contrasts with practices heretofore encountered inrecirculating conveyor arrangements, and is of significance inaccomplishing the desired results for the apparatus of the presentinvention. Particularly, it is to be noted that the normal position ofthe stabilizing rail means 61 (FIGS. 1 and 2) is overlying the deadplate 28, as after pushing of a temporary accumulated package back ontothe main conveyor line 10.

In the drawings and specification, there has been set forth a preferredembodiment of the invention, and although specific terms are employed,they are used in a generic and descriptive sense only and not forpurposes of limitation.

What is claimed is: 1. In a package transporting conveyor system havinga main conveyor line normally moving packages along a predetermined pathof travel, the combination therewith of means operable in the event ofblockage of packages from normal movement along the predetermined pathfor temporarily accumulating packages from the main conveyor line andsubsequently redelivering accumulated packages thereto, the accumulatingmeans comprising:

accumulating conveyor means mounted adjacent said main conveyor line forpackage transporting movement away from and toward said main conveyorline along a path perpendicular to said predetermined path of travel,

reversible drive means operatively connected to said accumulatingconveyor means for driving the same in package transporting movementaway from and toward said main conveyor line, and

control means operatively connected to said reversible drive means forcontrolling driving of said accumulating conveyor means and includingmeans for sensing the presence and absence of excessive numbers ofpackages on said main conveyor line, said control means responding tothe sensed presence of excessive numbers of packages on said mainconveyor line by initiating driving of said accumulating conveyor meansin movement away from said main conveyor line so as to move packagesaway from said predetermined path of travel and further responding tothe sensed absence of excessive numbers of packages on said mainconveyor line by initiating driving of said accumulating conveyor meansin movement toward said main conveyor line so as to return packages tosaid predetermined path of travel.

2. A conveyor system according to claim 1 wherein said main conveyorline and said accumulating conveyor means define generally horizontalpackage supporting surfaces lying substantially in a common plane andfurther comprising package stabilizing rail means mounted inpredetennined relation to said accumulating conveyor means for normallyforming a portion of an edge rail extending along said main conveyorline, said package stabilizing rail means being movable relative to saidmain conveyor line for engaging packages crowded onto said accumulatingconveyor means by the presence of excessive numbers of packages on themain conveyor line and thereby for facilitating maintenance of engagedpackages in their desired orientation on said package supportingsurfaces.

3. A conveyor system according to claim 2 wherein said packagestabilizing rail means is operatively connected to said accumulatingconveyor means for movement therewith in response to said drive meansdriving said accumulating conveyor means and for movement relativethereto in response to crowding of packages onto said accumulatingconveyor means from said main conveyor line.

4. A conveyor system according to claim 2 wherein said packagestabilizing rail means cooperates with said control means in sensing ofthe presence of excessive numbers of packages on said main conveyorline, said control means sensing movement of said package stabilizingrail means away from said main conveyor line in response to crowding ofpackages onto said accumulating conveyor means from said main conveyorline.

5. A conveyor system according to claim 1 wherein said accumulatingconveyor means comprises at least one flexible, endless loop conveyormember and sprocket means supporting said member for movement about apredetermined closed path of travel including a generally horizontalportion wherein said conveyor member defines a package supportingsurface and further wherein said reversing drive means is operativelyconnected to said sprocket means for driving said sprocket means in afirst rotational direction for movement of said conveyor member alongsaid horizontal path away from said main conveyor line and in a second,opposite rotational direction for movement of said conveyor member alongsaid horizontal path toward said main conveyor line.

6. A conveyor system according to claim 5 wherein said sprocket meanscomprises a driven sprocket mounted at a location remote from said mainconveyor line and operatively connected to said drive means fortransmitting to said conveyor member motive power driving said conveyormember both away from and toward said main conveyor line and furtherwherein said accumulating conveyor means comprises stationary supportmeans underlying said conveyor member along said horizontal path forcooperation with said sprocket means in supporting said conveyor member,said stationary support means extending from adjacent said main conveyorline to a point spaced from said driven sprocket for accommodating thepresence of a catenary curve portion of said conveyor member betweensaid driven sprocket and said stationary support means.

7. A conveyor system according to claim 1 wherein said means for sensingthe presence and absence of excessive members of packages on said mainline conveyor comprises a first sensing device positioned along saidmain conveyor line downstream of said accumulating conveyor means fordetecting crowding of packages therealong and a second sensing devicepositioned for detecting crowding of packages from said main conveyorline onto said accumulating conveyor means, said first sensing devicecooperating in said control means for determining the direction in whichsaid accumulating conveyor means is to be driven by said drive means andsaid second sensing device cooperating in said control means fordetermining when said accumulating conveyor means is to be driven.

8. A conveyor system according to claim 7 wherein said control meansfurther comprises means for sensing the presence on the accumulatingconveyor means of such conveyor line of such number of packages as tomomentarily fill the capacity of the main conveyor line to move packagesalong said predetermined path of travel, said control means beingresponsive to sensing of such capacity redelivery for interruptingdriving of said accumulating conveyor means toward said main conveyorline.

1. In a package transporting conveyor system having a main conveyor linenormally moving packages along a predetermined path of travel, thecombination therewith of means operable in the event of blockage ofpackages from normal movement along the predetermined path fortemporarily accumulating packages from the main conveyor line andsubsequently redelivering accumulated packages thereto, the accumulatingmeans comprising: accumulating conveyor means mounted adjacent said mainconveyor line for package transporting movement away from and towardsaid main conveyor line along a path perpendicular to said predeterminedpath of travel, reversible drive means operatively connected to saidaccumulating conveyor means for driving the same in package transportingmovement away from and toward said main conveyor line, and control meansoperatively connected to said reversible drive means for controllingdriving of said accumulating conveyor means and including means forsensing the presence and absence of excessive numbers of packages onsaid main conveyor line, said control means responding to the sensedpresence of excessive numbers of packages on said main conveyor line byinitiating driving of said accumulating conveyor means in movement awayfrom said main conveyor line so as to move packages away from saidpredetermined path of travel and further responding to the sensedabsence of excessive numbers of packages on said main conveyor line byinitiating driving of said accumulating conveyor means in movementtoward said main conveyor line so as to return packages to saidpredetermined path of travel.
 2. A conveyor system according to claim 1wherein said main conveyor line and said accumulating conveyor meansdefine generally horizontal package supporting surfaces lyingsubstantially in a common plane and further comprising packagestabilizing rail means mounted in predetermined relation to saidaccumulating conveyor means for normally forming a portion of an edgerail extending along said main conveyor line, said package stabilizingrail means being movable relative to said main conveyor line forengaging packages crowded onto said accumulating conveyor means by thepresence of excessive numbers of packages on the main conveyor line andthereby for facilitating maintenance of engaged packages in theirdesired orientation on said package supporting surfaces.
 3. A conveyorsystem according to claim 2 wherein said package stabilizing rail meansis operatively connected to said accumulating conveyor means formovement therewith in response to said drive means driving saidaccumulating conveyor means and for movement relative thereto inresponse to crowding of packages onto said accumulating conveyor meansfrom said main conveyor line.
 4. A conveyor system according to claim 2wherein said package stabilizing rail means cooperates with said controlmeans in sensing of the presence of excessive numbers Of packages onsaid main conveyor line, said control means sensing movement of saidpackage stabilizing rail means away from said main conveyor line inresponse to crowding of packages onto said accumulating conveyor meansfrom said main conveyor line.
 5. A conveyor system according to claim 1wherein said accumulating conveyor means comprises at least oneflexible, endless loop conveyor member and sprocket means supportingsaid member for movement about a predetermined closed path of travelincluding a generally horizontal portion wherein said conveyor memberdefines a package supporting surface and further wherein said reversingdrive means is operatively connected to said sprocket means for drivingsaid sprocket means in a first rotational direction for movement of saidconveyor member along said horizontal path away from said main conveyorline and in a second, opposite rotational direction for movement of saidconveyor member along said horizontal path toward said main conveyorline.
 6. A conveyor system according to claim 5 wherein said sprocketmeans comprises a driven sprocket mounted at a location remote from saidmain conveyor line and operatively connected to said drive means fortransmitting to said conveyor member motive power driving said conveyormember both away from and toward said main conveyor line and furtherwherein said accumulating conveyor means comprises stationary supportmeans underlying said conveyor member along said horizontal path forcooperation with said sprocket means in supporting said conveyor member,said stationary support means extending from adjacent said main conveyorline to a point spaced from said driven sprocket for accommodating thepresence of a catenary curve portion of said conveyor member betweensaid driven sprocket and said stationary support means.
 7. A conveyorsystem according to claim 1 wherein said means for sensing the presenceand absence of excessive members of packages on said main line conveyorcomprises a first sensing device positioned along said main conveyorline downstream of said accumulating conveyor means for detectingcrowding of packages therealong and a second sensing device positionedfor detecting crowding of packages from said main conveyor line ontosaid accumulating conveyor means, said first sensing device cooperatingin said control means for determining the direction in which saidaccumulating conveyor means is to be driven by said drive means and saidsecond sensing device cooperating in said control means for determiningwhen said accumulating conveyor means is to be driven.
 8. A conveyorsystem according to claim 7 wherein said control means further comprisesmeans for sensing the presence on the accumulating conveyor means ofsuch number of packages as to fill the capacity thereof for temporaryaccumulation of packages, said control means being responsive to sensingof such capacity accumulation for interrupting driving of saidaccumulating conveyor means away from said main conveyor line.
 9. Aconveyor system according to claim 7 wherein said control means furthercomprises means for sensing the redelivery from the accumulatingconveyor means to the main conveyor line of such number of packages asto momentarily fill the capacity of the main conveyor line to movepackages along said predetermined path of travel, said control meansbeing responsive to sensing of such capacity redelivery for interruptingdriving of said accumulating conveyor means toward said main conveyorline.